Humulin-N Human Insulin Injection U-100 Multiple Dose Vial 10 mL *Refrigeration* (Rx)Humulin N (Human Insulin NPH) 100 U mL Injection, 10 mL Vial Humulin N is a recombinant human insulin (NPH neutral protamine Hagedorn suspension) used to lower blood glucose in diabetes. Each milliliter contains 100 USP Units of human insulin (3. 5 mg) combined with protamine sulfate and zinc; this forms cloudy crystals that prolong absorption. The amino acid sequence of Humulin N insulin is identical to natural human insulin. By delaying absorption,